我只是想知道为什么当客户端连接时会崩溃??它应该是一个简单的 TCP 服务器,当客户端连接并发送一个字符串时,服务器以字符串中 A 的数量作为响应。一旦客户端输入一个字母,服务器就会崩溃。
#include<io.h>
#include<stdio.h>
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib") //Winsock Library
int main(int argc , char *argv[])
{
WSADATA wsa;
SOCKET s , new_socket, master;
struct sockaddr_in server , address;
int c, valread;
char *message = "Welcome to Marshall's TCP Server!!";
int MAXRECV = 1024;
char *buffer;
char AmmtA = 'a';
char AmmtB = 'A';
int count = 0, x;
fd_set readfds;
buffer = (char*) malloc((MAXRECV + 1) * sizeof(char));
printf("\nInitialising Winsock...");
if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
{
printf("Failed. Error Code : %d",WSAGetLastError());
return 1;
}
printf("Initialised.\n");
//Create a socket
if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
{
printf("Could not create socket : %d" , WSAGetLastError());
}
printf("Socket created.\n");
//Prepare the sockaddr_in structure
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( 9000 );
//Bind
if( bind(s ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
{
printf("Bind failed with error code : %d" , WSAGetLastError());
exit(EXIT_FAILURE);
}
puts("Bind done");
//Listen to incoming connections
listen(s , 3);
//Accept and incoming connection
puts("Waiting for incoming connections...");
c = sizeof(struct sockaddr_in);
while( (new_socket = accept(s , (struct sockaddr *)&address, &c)) != INVALID_SOCKET )
{
puts("Connection accepted");
send(new_socket , message , strlen(message) , 0);
valread = recv( new_socket , buffer, MAXRECV, 0);
if( valread == SOCKET_ERROR)
{
int error_code = WSAGetLastError();
if(error_code == WSAECONNRESET)
{
//Somebody disconnected , get his details and print
printf("Host disconnected unexpectedly , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));
//Close the socket and mark as 0 in list for reuse
closesocket( s );
}
else
{
printf("recv failed with error code : %d" , error_code);
}
}
if ( valread == 0)
{
//Somebody disconnected , get his details and print
printf("Host disconnected , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));
//Close the socket and mark as 0 in list for reuse
closesocket( s );
}
else
{
for (x = 0; buffer[x] != '\0'; x++) {
if (buffer[x] == AmmtA || buffer[x] == AmmtB)
count++;
}
char feedback[150];
sprintf(feedback, "There is %d A's in your string", count);
feedback[MAXRECV] = '\0';
printf("%s:%d - %s \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port), buffer);
send( s , feedback , MAXRECV , 0 );
}
free(buffer);
}
if (new_socket == INVALID_SOCKET)
{
printf("accept failed with error code : %d" , WSAGetLastError());
return 1;
}
closesocket(s);
WSACleanup();
return 0;
最佳答案
10057 - WSAENOTCONN - 套接字未连接。
发送调用是正确的,它使用了 new_socket。但是 recv 调用使用 socket/sd“s”。 recv 调用也应该使用 new_socket。
返回错误10057是因为s只绑定(bind)了本端,没有连接远端,而accept返回的新socket连接的是远端。
关于c - TCP 服务器崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35692129/